1. Field
Example embodiments relate to nano-imprint lithography methods for forming a pattern on a substrate with reduced pattern errors by using a mold having an area smaller than an area of the substrate.
2. Description of the Related Art
Generally, nano-imprint lithography is a technology in which a substrate is etched using a resin pattern as an etching mask. Conventionally, the resin pattern is formed by an imprint process. In an example imprint process, thermoplastic resin or photo-curable resin is applied over a substrate, and then the resin is cured while being pressed by a mold formed with a nano-scale pattern having a line width of 1-100 nm.
As compared to conventional photolithography methods, the above-described nano-imprint lithography method realizes formation of a nano-scale pattern via a relatively simple process, and thus, presents relatively high production efficiency, relatively low manufacturing costs, etc. For this reason, nano-imprint lithography methods are receiving considerable attention as a technology for forming circuits for next generation semiconductors and flat panel displays.
This particular nano-imprint lithography method requires a mold having a nano-scale pattern imprinted by electron-beam (e-beam) lithography or laser lithography.
Moreover, forming a pattern on a relatively large-area substrate using such a nano-imprint lithography method requires a relatively large-area mold. However, fabrication of such a relatively large-area mold is relatively difficult. Therefore, a pattern is formed on a relatively large-area substrate using a method in which resin patterns are repeatedly formed on a relatively large-area substrate using a relatively small-area mold prior to etching the substrate. However, the proposed conventional method, in which the relatively large-area substrate is etched after the resin patterns are repeatedly imprinted on the substrate may cause pattern errors because boundaries of the repeatedly imprinted resin patterns are inconsistent. In more detail, when resin is applied to the entire surface of a substrate and resin patterns are formed by imprinting a first region of the substrate and immediately imprinting an adjacent second region of the substrate, the resin applied to the second region is cured along with the resin applied to the first region during imprinting of the first region. This causes pattern errors at boundaries of the resin patterns. Accordingly, when the substrate is etched using the resin patterns as an etching mask the substrate has pattern errors.